This invention relates generally to the art of cathode sputtering, and more particularly to the art of reconditioning the anode in a cathode sputtering apparatus.
U.S. Pat. No. 4,379,040 to Gillery describes a method and apparatus for the control of reactive sputtering deposition of oxide-containing films, including the steps of monitoring the deposition rate and total pressure of the system, and maintaining them at a constant level by adjusting the oxygen and argon input flow rates. Gillery discloses producing a transparent electroconductive article by sputtering an inner transparent film of titanium oxide onto a transparent substrate, depositing a transparent electroconductive metal film onto the inner titanium oxide film, and sputtering an outer transparent film of titanium oxide onto said electroconductive film.
U.S. Pat. No. 4,166,018 to Chapin describes a sputtering apparatus in which a magnetic field is formed adjacent a planar sputtering surface, the field comprising arching lines of flux over a closed loop erosion region on the sputtering surface.
A problem associated with the cathode sputtering of dielectric films such as titanium oxide is that the coating material is incidentally deposited onto the anode in the sputtering system as well as onto the substrate. As dielectric coating material builds up on the anode surfaces, the bias voltage of the anode increases, the anode becomes increasingly less effective, and coating uniformity deteriorates substantially. As a result, in order to achieve a uniform coating, the anode must be periodically reconditioned by cleaning, i.e., physically removing the dielectric coating material contamination from the anode surface. This reconditioning procedure is time-consuming and costly as it requires discontinuing the sputtering process, and removing the anode from the coating apparatus to avoid contaminating the sputtering environment as the anode is cleaned.